I have a 54 XK120SE OTS and it has a bad habit of starting right up when I leave the house, but not starting a second time unless I wait for the car to cool completely down. I've tried disconnecting the temperature sensor on the automatic choke, but that doesn't seem to work. I've also replaced the coil on site (thanks to Dick Cavicke for the assist!) and that didn't work either. By the time Dick took his coil off the car and replaced mine, however, my car had cooled sufficiently to start right up again. This is, to put it mildly, disconcerting as I love to drive the car, but my wife and I are hesitant to take it for a spin because we don't know if it'll start a second time. Any thoughts?

Submitted by woebegone@mind… on Tue, 11/02/2010 - 23:24

You ever seen the size of the #3 main and thrusts on a flatmotor?

In 45 years of working on flatties, I have never, as in ever, seen a bad thrust or a crank damaged in the thrust area.
Doesn't mean it never happens, just never seen it.

Really, it's just the additional drag of the T/O bearing, methinks.

Submitted by woebegone@mind… on Sun, 10/31/2010 - 00:51

This isn't a Jag, and end-float is, in fact, correct.
Flathead V-8, to be precise.
1950 to be exact.

Has more to do with the load on the BIG thrust ends and a six-volt system.

I can get it almost gone, but not quite.

Submitted by bonnettoboot@e… on Sun, 10/31/2010 - 00:41

Dave, your quirk is in fact rather common, particiularly on older engines, this means that the crankshaft end float is excessive, as a result the con rods are moved out of line causing them to bind !!

Submitted by craig.m@roadru… on Sun, 10/31/2010 - 00:34

Dave,

You're continuing to give me good information. I'm actually taking the car to a Scottish gentleman who I've used before for restoration work and he's really familiar with 120's. I'm hoping between his knowledge and your input we can solve this problem.

To answer your service writer questions (good job there!):

The crank speed does seem just a bit slow. Every now and then it comes really close to starting, will percolate for just a second and then go back to cranking again.

Go figure on your clutch! I"ve driven cars that I've felt you had to hold your head in just the right position to get things started so maybe there's something to the physics of how a driver is positioned in the car!

Submitted by craig.m@roadru… on Sat, 10/30/2010 - 20:09

Dave,

You're continuing to give me good information. I'm actually taking the car to a Scottish gentleman who I've used before for restoration work and he's really familiar with 120's. I'm hoping between his knowledge and your input we can solve this problem.

To answer your service writer questions (good job there!):

The crank speed does seem just a bit slow. Every now and then it comes really close to starting, will percolate for just a second and then go back to cranking again.

Go figure on your clutch! I"ve driven cars that I've felt you had to hold your head in just the right position to get things started so maybe there's something to the physics of how a driver is positioned in the car!

Submitted by woebegone@mind… on Sat, 10/30/2010 - 19:49

From my days of "writing service", and having to learn how to ask questions to see where we're headed...
Cranks but not enough?
As in, cranks but not fast enough?
"Yes, it cranks fine, but not enough to actually fire up."

Sometimes, speed is a definite issue.....dragging starters (heat soak), bad grounds....many things can contribute.

I have a car, that will not start hot if you hold the clutch down.
Have to set the brake, find neutral, pedal out, THEN it starts right ip.

Submitted by craig.m@roadru… on Sat, 10/30/2010 - 19:47

Hi Dave,

Yes, it crankjs fine, but not enough to actually fire up. There is fuel at the carbs as well...checked that. I have not heard of the wet rags on the fuel lines trick however. I've actually replaced the coil (still have the original as I didn't think the coil was the problem) once, but who knows whether the new one has issues. That needs to be checked. I sincerely appreciate your thoughts Dave.

Submitted by craig.m@roadru… on Sat, 10/30/2010 - 19:00

Edited on 2010-10-30 19:48:31

Hi Dave,

Yes, it cranks fine, but not enough to actually fire up. There is fuel at the carbs as well...checked that. I have not heard of the wet rags on the fuel lines trick however. I've actually replaced the coil (still have the original as I didn't think the coil was the problem) once, but who knows whether the new one has issues. That needs to be checked. I sincerely appreciate your thoughts Dave.

Submitted by woebegone@mind… on Sat, 10/30/2010 - 18:54

Just a troubleshooting question, based on years of auto repair.
By "not starting", do you mean cranks normally but won't catch, or won't crank?
Next, is there actually fuel at the carbs?
Having several cars owned, and many I've worked on with "heat soak" issues, could you be having a spot vapour lock under the bonnet or at the carbs themselves?

Wet rags on the fuel lines has helped us isolate this issue before, on the road, just dumping water on the lines and carbs, but on a restored engine bay, that isn't a good idea.

When it does this, and if it cranks normally, I would A) check for full voltage at the coil, B) try the wet rags, then C) pull one plug and see if it's wet or dry.

But, that's just me.

Dave